The Briefcase 6: What’s So Big About the Big Four?

Every profession has its royalty. Musicians have Beyoncé, football has Messi, and accounting has… Deloitte, PwC, EY, and KPMG. The Big Four.

They’re the firms your non-accountant friends might have actually heard of (and will still confuse with each other). They dominate the profession in a way that makes everyone else look like plucky underdogs. But how did we end up with just four? And will it stay that way?

📜 A Brief History of Shrinkage

Once upon a time, there were the Big Eight: Arthur Andersen, Arthur Young, Coopers & Lybrand, Deloitte Haskins & Sells, Ernst & Whinney, Peat Marwick Mitchell, Price Waterhouse, and Touche Ross. Through mergers and consolidations, they became the Big Six, then the Big Five.

The turning point came in 2002, when Arthur Andersen collapsed in the wake of the Enron scandal, leaving us with the Big Four – Deloitte, PwC, EY, and KPMG – that dominate global accounting today.

🌍 What Makes Them Big Anyway?

Sheer scale. The Big Four have offices in more countries than most people remember. They audit the majority of the world’s largest listed companies, and their combined revenues are bigger than the GDPs of some small nations.

More importantly, their dominance is not just legendary, it’s measurable:

• The Financial Reporting Council (FRC) reports that the Big Four earned 98% of all FTSE 350 audit fees in 2022, underscoring how every major public interest entity relies almost exclusively on them for audits.
• In 2023, challenger firms won just 13% of FTSE 350 audit engagements, up slightly from previous years – yet the Big Four still hold the remaining 87%.

This matters because audit isn’t just box-ticking. It’s the backbone of financial trust – what keeps regulators, investors, and markets breathing easy. And right now, those checks mostly go through the Big Four.

📈 Could We See a Big Five Again?

Every few years, someone predicts a shake-up. Could another firm muscle into the elite club? Or will one of the Four stumble and shrink it further?

Let’s look at the numbers. The Big Four aren’t just ahead – they’re in a different league:

• Deloitte: US $67.2 billion revenue, ~460,000 employees (2024)
• PwC: ~US $55.4 billion revenue, ~370,000 employees (2024)
• EY: US $51.2 billion revenue, ~393,000 employees (2024)
• KPMG: US $38.4 billion revenue, ~275,000 employees (2024)

Now compare that to the ‘next tier’:

• BDO: ~US $14 billion revenue, ~115,000 employees (2023)
• RSM: ~US $9 billion revenue, ~64,000 employees (2023)
• Grant Thornton: ~US $7 billion revenue, ~68,000 employees (2023)

It’s not just a gap, it’s a canyon. Deloitte alone earns more than all three challengers combined, and has four times the headcount of BDO.

So, could we see a Big Five again? Possible, but unlikely. Unless one of the Big Four implodes, the gulf in scale, global reach, and brand recognition is massive. Challenger firms are growing, but they’re still playing in a very different weight class.

👔 What’s It Like Working at a Big Four Firm?

If you’ve ever met someone who’s done their time in the Big Four, you’ll know it leaves a mark – good or bad. On the plus side, the name carries huge weight. Recruiters openly admit to filtering CVs for Big Four company names. Having it on your résumé can open doors into C-suite roles, Fortune 500 companies, or even tech startups. The alumni network alone is worth its weight in LinkedIn connections.

But the flip side? The corporate grind is legendary. Long hours, high pressure, and a culture that can be punishing to your health.

The experience itself is also mixed. At a Big Four firm, you might spend months buried in just a handful of accounts for a single giant client. By contrast, regional firms often give you exposure to the whole balance sheet. Great for depth at the Big Four, better for breadth elsewhere.

So, is it worth it? If you want prestige, global mobility, and long-term career options – yes. For many, it’s a launchpad. But if you’re chasing work-life balance, variety, or a less brutal grind, the shine can wear off fast.

🧠 Final Thoughts

The Big Four are big because they’ve become more than firms – they’re institutions. They dominate global audit, churn out legions of accountants, and hoover up consulting gigs like they’re the last sausage rolls at a conference buffet.

Will they stay four forever? Maybe. But if history tells us anything, it’s that nothing is permanent in accounting. Not even ‘permanent differences’.

So next time someone asks you "what’s so big about the Big Four?” you can tell them: money, history, and the fact that they’ve cornered the market on being just too big to fail.